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-rw-r--r--arch/x86/kernel/cpu/perf_event.c20
1 files changed, 20 insertions, 0 deletions
diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c
index ed6310183efb..6d75b9145b13 100644
--- a/arch/x86/kernel/cpu/perf_event.c
+++ b/arch/x86/kernel/cpu/perf_event.c
@@ -381,6 +381,20 @@ static void release_pmc_hardware(void) {}
381 381
382#endif 382#endif
383 383
384static bool check_hw_exists(void)
385{
386 u64 val, val_new = 0;
387 int ret = 0;
388
389 val = 0xabcdUL;
390 ret |= checking_wrmsrl(x86_pmu.perfctr, val);
391 ret |= rdmsrl_safe(x86_pmu.perfctr, &val_new);
392 if (ret || val != val_new)
393 return false;
394
395 return true;
396}
397
384static void reserve_ds_buffers(void); 398static void reserve_ds_buffers(void);
385static void release_ds_buffers(void); 399static void release_ds_buffers(void);
386 400
@@ -1372,6 +1386,12 @@ void __init init_hw_perf_events(void)
1372 1386
1373 pmu_check_apic(); 1387 pmu_check_apic();
1374 1388
1389 /* sanity check that the hardware exists or is emulated */
1390 if (!check_hw_exists()) {
1391 pr_cont("Broken PMU hardware detected, software events only.\n");
1392 return;
1393 }
1394
1375 pr_cont("%s PMU driver.\n", x86_pmu.name); 1395 pr_cont("%s PMU driver.\n", x86_pmu.name);
1376 1396
1377 if (x86_pmu.quirks) 1397 if (x86_pmu.quirks)